Color photography



June 16,` 1931. v, D, KELLEY ,l 1,810,180

COLOR PHOTOGRAPHY Filed Deer.' 12v, 1922 @-1 ily-z @-3 GREEN PRINTERPff/11TH?. ms'a NEG/471V: Pos/Tiri of' cnice/y sq/mv:

.Wr 4 Wr 5 DyEl; :Mul-avan- .Hrrrn rms-r PRIN-r PROM f' Bv .AFTERarco/v0 PRI/YT Z from a coMPLEMb-NTIRY l 4 GREEN w11. 0E PRI/VIERATTORNEY' l Patented June 16, 1931 UNITED STATES PATENT OFFICE WILLIAMV. D. KELLEY, OF JERSEY CITY, NEW JERSEY, ASSIGNOR, BY MESNE ASFSIGNMENTS, T0 MAX B. DU PONT VITACOLOR CORPORATION, OF LOS ANGELES,CALI- FORNIA., A CORPORATION 0F DELAWARE COLOR PHOTOGRAPHY Applicationled December 12, 19.22, Serial No. 608,869, and in Great Britain August13, 1921.

.single coated emulsion which was then resensitized by bichromating forthe second print, with both positive images in dye, giv- Y ing extremetransparency. l

In the accompanying drawings, l Figure 1 represents an object, Fig. 2 ared color'value negative,

Fig. 3 a green color value negative,

Fig. 4 represents the green printer, or red value negative,

Fig. 5 the red value printing positive,

Fig. 6 the green colored positive image,

Fig. 7 the red colored positive image,

Fig. 8 the final projecting positive,

Fig. 9 is a cross-section of the film before printing, c Fi 10 is a'cross-section of the film after the rst print, and

Fig. 11 is a similar view after the second print.

In this invention, an improvement is introduced first in the characterof positive single coated stock used, and secondly by reason thereof, inthe treatments for producing the color images. The positive stock inthis in-V vention consists of ordinary emulsion provided with a lightretarding fugitive dye, as for example tartrazin, as set forth in myapplication Ser. No. 383,648, filed May 24, 1920,

.I of which application this application is a continuation in part.

y The first print is made, for exam le, from the red valuev negativethrough t etransparent support to the inner stratum ofthe positiveemulsion to produce whatis hereinafter termed a green value diapositiveprint without affectingA the outer stratum, followed' registrationmethod shown in Patent No.`

1,350,023, August 17, 1920, Will be suitable for contact printing, whichis referred, but the two images can be printed y contact, or optically,or simultaneously if desired. The prints may be successively made if thenegatives are on single strip, but if the printing negatives (negativeand printer positive) are on separate st-rips, as will usually result bymaking the printer positive from one of the original negatives, bothprints may be made at the same time. In either case, 4the emulsion isimpregnated with the fugitive dye to prevent printing through, asprimarily it is desired that one print be in the stratum of emulsionnext the support, and the other print in the outer stratum of emulsion.This leaves an intermediate stratum practically unaffected, exce t whereone negative is thin or is overprlnted. Preferably, the bottom or innerprint will bel made the heavier, so that a sli ht reduction from thebleach for the outer lmage will be -helpful in clearing the inner image.

Upon iirst washing out the yellow fugitive dye, and then developing theprints, there results a composite print composed of a diapositive and-adianegative in reduced silver, in different strata of a single layer ofemulsion. These prints are not fixed out at this time but may be handledin artificial light, and the unfixed silver salt will act as an aid injudging of the completion of the next operation."

The film is now placed in a bath having the property of hardening thegelatine surrounding the developed silver and at the same time bleachinga silver image. This bath is also'characteristically slow enough inpenetrating the gelatine as to completely bleach the top dianegativeimage before acting on the lower or diapositive image next the support.A slight reducing effect of the bleach on the lower image does no harm.The film is submerged in the-bleach bath for about thirty seconds, oruntil thesurface image is bleached.

Such a bleach is described in Brit. J rl. Phot. Supt. p. 36, May. 7,1909. The action of the bleach is to remove the dianegative convertedsilver image by rendering it invisible and transparent, and at the sametime hardening or tanning the gelatine in situ therewith so as to rendersuch image dye repellent to a gelatine dye, whereas the remainder of thegelatine will absorb dye. The bleach also clears the inner image byslight reduction. The progress can be easily watched as the outer imagedisappears first and the reduction of the inner can be watched andstopped at the right time.

A suitable bath is:

Potassium ferricyanide 9 gms. Potassium bromide 14 gms. 'Potassiumbichromate 9 gms. Glacial acetic acid 3 cc.

Potassium alum 15 gms.

Water 2000 cc.

After Washing, the Hlm is fixed out in plain sodium thiosulphate,leaving the surface hardened where the silver of the dianegativepreviously existed, and an unbleached black silver'image representing adiapositive print of the red negative. In other words, only a singlerecord is now discernible, this being .the inner one lying next thesupport. This silver image (the green value diapositive) from the redvalue negative is now converted to a dye toned green image, or achemically toned green image, is then fixed out in sodium thiosulphate,and thoroughly' dried. The toning baths intensify the inner image.

If the inner image (the green value diapositive) is to be dye toned, itis bleached in a bath that will give a vanadium yellow mordant, `as bybleaching in the following bath for about six minutes:

Vanadium oxalate 10% solution 50 cc. OXalic acid 10 gms. Potassiumferricyanide 10 gms.

Water 2000 cc.

about three minutes Vto dye the top negative gelatine image, and washedfor two minutes. After drying, the film is ready to project or View.This dye has the characteristic of readily dying soft gelatine, whileleaving the hardened gelatine unaffected.

Or for the bottom image, the dyetoning method disclosed in my Patent No.1,411,968 dated April 4, 1922, may be utilized. In which event afterbleaching the inner image (the green value diapositive) as thereindescribed, and after bleaching the outer image (the red valuedianegative) as herein described, two dyes of the acid family may beused, wool green S, (sodium salt oftetramethyl-diaminodiphenyl-beta-hydroxynaphthyl-carbinol disulphonicacid anhydride) the salt of a sulphonic base for the inner image, andred acid dye commonly known as pinatype red D dye, such as used in thepinatype process, or a dye, derived from a similar salt for the outerimage.

The bottom image (the green value diapositive) `may be toned in uraniumby using a bath such as the following, which mordants basicv red dyes toenrich the color. In this case, green dyes are used for the surfaceimage (the red value dianegative).

Water L8000 cc.

Uranium nitrate 288 gms. Potassium oxalate 96 gms. Hydrochloric acid 672cc.

The color schemes are therefore reversible. As an aid to the surfacehardening of the surface image a pyro developing bath may be usedcomposed of:

Pyrogallic acid 5 gms. Sodium sulphite 20 gms. Sodium carbonate 25 gms.Potassiumbromide 1 gm. Distilled water 1000 cc.

The step of using a preliminary bath for removing the fugitive dye is ofadvantage and should be by washing in water at a temperature of 650which will cause the gelatine to swell, and increase the separationbetween the bottom and top images.

By utilizing a diapositive image on the top and totally removing thesilver without depending on a silver image as a means for mordantirig ortoning a color, thereis a condition present particularly favorable tothe production of outer print for the lreason that should the initialbleaching affect the bottom image, it can do no harm by degrading it.The lower image could be entirely ruined for the purpose of thisinvention if the bleaching is carried too far, without disadvantage asit would be removed upon fixing. A slight action on the lower image doesno more than reduce its intensity.

If it is desired to chemically tone the bottom image blue, the film islimmersed for four Water 2000 cc.k

After using the bichromate ble-ach bath for the-first image, a bath forthree minutes in a .5% ammonia solution may be given as anaid to`removing the bichromate.

In the drawings, the object in Fig. 1, from which the negatives of Figs.2 and 3 are made, is composed of black, red, green and white sections B,R, G, IV. Figs. 4 and 5 show the printer negatives, Fig. 5 being apositive of Fig. 3. Figs. 6 and 7 show the respective colored printsfrom Figs. 4 and 5, and Fig. 8 the finished positive.

In this process, the finished print at the time of coloring has only onesilver record. There are two silver records immediately afterdevelopment, but when the silver that has not been light affected isfixed out, there` is only onesilver image to control or color.

All of the operations can consequently be simple. tank operations undercomplete supervision;

By toning is meant broadly thecoloring of an image, While by chemicaltoning is meant coloringpby a salt of a metal Whether subsequentlyintensified by a dye or not, and by dyeing or dye toning is meantcoloring of a treated image with soluble dye.

I claim:

1. Process of4 producing two differently colored prints in a singlesilver Vhalid emulsion consisting infprinting a diapositive and adianegative image of the same subject in registration in differentstrata of the emulsion, developing the respective prints, rendering thedianegative print invisible, and

ldifferently coloring the respective prints.

2". Process of producing two differently colored prints in a singlesilver halid emulsion consisting in printing a diapositive and adianegative imageof the same subject in registration in different strataofi4 the emulsion, developing the'respective prints, removing thedianegative print, and differently coloring the respective prints. l i3. Process of producing two complemen.

tary prints in a single silver halid emulsion,

consisting in forming in registration, a diapositive-and a dianegativesilver print in different strata of the emulsion `from complementarycolor value images of the same subject-,treating the stratum carryingthe dianegative print to renderthe silver image transparent and dyerepellent while retaining dye absorptiveness in the remainder of saidstratum, dyeing such remaining portion to form one color print, andcoloring the other print in the other stratum.

4. Process of producing two complementary prints in a single silverhalid emulsion, consisting in forming in registration a diapositive anda. dianegative silver print in different strata of the emulsion fromcomplementary color value images of the same subject, bleaching thedianegative print and hardening the gelatine in situ therewith to renderthe image transparent and repellent to a gelatine dye. dyeing theremaining gelatine diapositive image, and coloring the positive silverimage in the other stratum.

5. Process of producing two complementary colored images in the sameemulsion, which consists in printing a diapositive and a dianegative ina single emulsion, hardening and removing the dianegative surfacerecord, I

toning the silver image, and dyeing the soft rendering the gelatine insitu therewith re-v pellent to dye without affecting the receptivity todye of the remaining gelatine in the same stratum, dyeing such gelatineto form one diapositive image, coloring the other imagewithgcomplementary color, and fixing both images.

8. Process of `producing twodi'fferently colored prints in a singlesilver halid emulsion consisting in printing a diapositive and adianegative image of the same subject in different strata of a singleemulsion, bleach ing the dianegative and reducing the diapositiveimages, toning the diapositive image to one color, and dyeingthe imagein the vother stratum to another color.

9. Process of producing tWo differently colored prints in a singlesilver halid emulsion consisting in printing a diapositive andadianegative image of the same subject in different strata of a singleemulsion, bleachving the dianegative and reducing the Vdiapositiveimages, fixing, chemically toning the diapositive image to one color,and dyeing the image in the other stratum to another color. Y

10. Process' of producing twoy differently colored prints in a singlesilver halid emulsion consisting in printing a diapositive in the innerstratum of the emulsion and a diane'gative in the outer stratum,bleaching the dianegative and reducing the diapositive in'1- ages,chemically toning the diapositive ini age to one color and dyeing theimage in the other stratum to another color.

11. Method of producing a color photogra-ph by blending dierentlycolored images within the same emulsion and comprising printing;- andthen developing silver images in different strata of said carrier fromcolor value negatives, differently converting both images for coloring,and tixing' di'liperent color images by the agency ot' said differentlyconverted images.

12. A color transparency in a single colloid layer comprising in onestratum a diapositive silver print colored, and in the other stratum aprint having a transparent bleached dianegative portion and a gelatinedyed positive portion. A

13. A color transparency in a single colloid layer comprising` in theinner stratum adjacent the support, a diapositive colored color valueimage7 and in the outer stratum an invisible uncolored dianegative and adye positive complementary in color and value with the first image.

. 14. A color transparency in a single colloid layer comprising in theinner stratum adjacent the support a diapositive colored color valueimage, and in the outer stratum an invisible uncolored dianegative and adye positive complementary in color andvalue with the first image, bothsaid diapositive and dianegative being derived from sensitive silversalt originally containedin the emulsion.

15. A color transparency comprising? in aY single layer of colloidemulsion having in one stratum a silver print, and in the other stratuma dianegative silver print oit' the same subject.

16. A color transparencycomprising in a single layer of colloid emulsionhaving in one stratum a silver print, and in the. other stratum adianegative silver print of the same subject in registration.

17. A color transparency comprising in a single layer of colloidemulsion having in the inner stratum a silver print, and inthe outerstratum a dianegative silver print of the same subject..

18. A color transparency comprising a single layer of colloid emulsionhaving in the innerlstratum next the transparent support a. partiallyreduced diapositive silver print and in the outer stratum a positiveimage capable of' taking dye.

19. A color transparency comprising a single layer of colloid emulsionhaving in 'the inner stratum next the transparent support a partialyreduced diapositive silver print

